1. Field of the Invention
The present invention relates to a rigid telescopically arranged multi-cavity dispensing container for a flowable material, such as toothpaste and the like, from which it is desired to dispense simultaneously two or more reactive substances which require separate storage until time of use.
2. Prior Art
There exists a desire to provide sodium bicarbonate and peroxide gel as components of toothpaste. Sodium bicarbonate is a well known and commonly used abrasive and cleaner. Peroxide gel is regarded as a beneficial ingredient to help promote healthy gums. These components are reactive when mixed, and therefore must be maintained separately until time of use.
U.S. Pat. No. 4,742,940 to Wilkinson discloses a basic single cavity dispenser. A hollow upper cylinder filled with a single flowable material has a dispensing spout but is otherwise closed at its upper end. A piston is arranged for telescopic upward movement within the upper cylinder so as to force a stream of flowable material through the spout upon relative compression of the piston and cylinder.
U.S. Pat. No. 4,747,517 to Hart discloses a single cavity container for simultaneously dispensing increments of two extrudable materials that polymerize when mixed. The two materials are separated by an extrudable barrier layer which prevents intermixing of the materials until after they emerge from the outlet. A piston slidably mounted within the cavity acts to force the materials through a specially-adapted mixing nozzle so that the materials emerge in an already-mixed state. The nozzle must then be removed and replaced after each use because of the trapped epoxy mixture which later hardens and clogs the passageway.
U.S. Pat. No. 3,166,221 to Nielsen discloses a rigid piston-type, double-tube dispensing container with a rigid barrier separating the two compartments. When the tube member is pushed down into the housing member, the contents will be pressed out through two separate nozzles. The contents emerge in the shape of two separate but closely juxtaposed bands which are difficult to dispense neatly onto the narrow width of a toothbrush.
U.S. Pat. No. 4,687,663 to Schaeffer discloses various configurations for simultaneously dispensing hydrogen peroxide and sodium bicarbonate. A rigid pump-type dual-cavity dispenser has two closely-positioned but separate outlets producing a double material stream which is difficult to apply to the narrow width of a toothbrush surface. Also disclosed is a collapsible tube separated into two compartments by a divider which extends to the rim of the mouth. Such an embodiment fails to take into account the possibility that the two components might have different rheologies, which will result in improperly proportioned quantities of the two materials being dispensed when the tube is squeezed.
U.S. Pat. No. 4,487,757 also discloses a toothpaste tube with separate compartments with a divider extending to the dispensing nozzle. Experimentation has shown that embodiments of this patent and the Schaffer patent tend to dispense the dual materials in an uncontrolled manner, for example, there is a tendency to dispense the dual material in uncontrolled varying proportions. Dispensing of the dual materials in predetermined proportions becomes even more difficult if the materials are of different rheologies. In addition, in certain embodiments there is a tendency of the materials to curl away from each other as they emerge from the nozzle, making it difficult to provide efficient dispensing onto a toothbrush.
It is thus an object of the present invention to provide a rigid piston-type multi-cavity dispensing container for simultaneous coextrusion in predetermined proportions of two or more flowable materials, which may have different rheologies, such as two components of a toothpaste and the like which, upon relative compression of the upper and lower body members, produces a single, banded, unmixed stream of material that can be neatly and easily applied onto the narrow width of a toothbrush.
It is a further object to provide such a dispenser which dispenses a single stream of unmixed material and which provides segregation of the component materials within the dispenser both prior to and after dispensing.